JP2003182087A - Method of manufacturing share mode inkjet head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a high quality share mode inkjet head whereby precise electrodes in high density and precise solid wiring patterns in high density can be formed by a simple and highly reliable method as compared to heretofore and leakage of ink, or falling or cracking of a partition wall between channel grooves does not occur. <P>SOLUTION: A piezoelectric element plate is subjected to mechanical grinding to form the channel grooves 2. After vertical grooves 6 communicating with the channel grooves 2 are formed by emitting a laser light, the plate is subjected to electroless plating. A head substrate 5 is abraded to form longitudinal wiring patterns. The laser light is emitted to the head substrate 5 to form lateral wiring patterns communicating with the longitudinal wiring patterns. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-speed, high-density, high-quality high-quality shear mode inkjet head, an electrode,
Regarding the novel method of forming a three-dimensional extraction wiring from the electrode, in more detail, by forming a three-dimensional extraction wiring with the electrode by forming a plated metal layer, irradiating laser light and polishing, Simple and reliable,
The present invention relates to a method for manufacturing a high-quality shear-mode inkjet head that does not cause ink leakage.

[0002]

2. Description of the Related Art The principle of a shear mode ink jet head is to grind a number of parallel channel grooves in a polarized piezoelectric element plate and use these as ink grooves, and electrodes are provided on the side walls of the ink grooves to generate an electric field. When applied, the side wall between each ink groove is deformed in the shear mode, pressure is applied to the ink, and the ink is ejected. Since the side wall of the ink groove is deformed to eject the ink, when the ink is ejected, the vibration is transmitted to the adjacent groove, and not only the ink meniscus of the ejected ink groove but also the meniscus of the ink grooves on both sides vibrate. Until the vibration of the meniscus stops, the ink cannot be ejected not only from the ejected ink groove but also from the ink grooves on both sides.

Therefore, when ink is to be ejected from a large number of ink grooves at the same time, for example, when ejecting from all ink grooves, it is necessary to separate two or more ink grooves that can be ejected at the same time, and every other ink groove. A three-cycle ejection method is used in which the ink groove is divided into three groups and the ink is ejected three times. However, in this case, since the ink cannot be ejected simultaneously from all the ink grooves, the effect of improving the printing speed per channel cannot be expected.

Further, the ink grooves for ink ejection and the air grooves for which ink is not ejected are alternately provided by using the channel grooves so that the vibration of ejection does not reach the adjacent ink grooves. There is also known a head capable of simultaneously ejecting ink from the ink jet head and greatly improving the printing speed per channel.

In order to manufacture such a shear mode ink jet head, it is necessary to grind the channel grooves in the piezoelectric element plate, form electrodes in each channel groove, and form wiring for sending a signal to the electrodes. is there.

FIG. 15 shows an example of a conventional shear mode ink jet head. In this shear mode inkjet head, the channel groove 1 is formed by forming a plurality of channel grooves 103 parallel to the piezoelectric element plate 100.
03 and partition 102 are formed alternately. Each channel groove 103 has a depth equal to the ink inlet end (on the right rear side in the drawing).
The groove is sealed by gradually shallowing toward, and ink is supplied from the opening 101a of the top plate 101. With this shape, when the roof portion of the partition wall 102 is masked and aluminum is vapor-deposited and then the mask is removed, the electrode 104 is formed inside the channel groove 103, and at the same time, the lead wiring 104a is formed in the shallow groove portion 103a and the unground portion 100a. , This lead-out wiring 104a to wire bonding or A
CF (anisotropic conductive film) can be connected to a drive circuit via a flexible cable. That is, when the electrode 104 is formed in each channel groove 103, the lead wiring 104a can be formed at the same time.

However, in order to form the shallow groove portion 103a,
Since the dicing saw having a diameter of several cm must be gradually lifted and ground, the shallow groove portion 103a and the unground portion 100a occupy about half of the head volume.
The shallow groove portion 103a can hardly deform the partition wall 102 even when a voltage is applied. Also, this part is the top plate 101.
Since the opening 101a is formed by cutting out the hole, the generated pressure escapes to the manifold side and hardly contributes to ink ejection. Furthermore, the unground portion 100a cannot contribute to ejection at all.

In the figure, 105 is a nozzle plate joined to the outlet end of the ink groove 103, and 106 is the nozzle plate 105.
Nozzle holes for ejecting ink perforated in the printed circuit board, 107 is a printed circuit board, and 108 is wire-bonded wiring for electrically connecting the lead-out wiring 104a and the printed circuit board 107.

The shear mode ink jet head is
Since the piezoelectric element plate is sandwiched between the electrodes, the operation is the same as that of the capacitor, and as described above, the electric charge is also accumulated in the portion that does not contribute to the ejection. Therefore, the electrostatic capacity of the head becomes large, and even if a high frequency signal is applied to the head, the response is delayed and high-speed driving cannot be performed. In addition, there is a drawback that the piezoelectric element plate has a large hysteresis loss, and remarkably generates heat.
Further, depending on the type of image, if there is a channel groove that frequently ejects ink and a channel groove that does not eject much, the temperature of the channel groove that ejects frequently rises, so the ink temperature in the channel groove rises and The viscosity is reduced and the speed of the ejected droplet is increased. When the ejection speed changes due to the channel groove, the landing position of the ink on the medium is disturbed, so-called print pattern-dependent crosstalk occurs, and the image quality deteriorates significantly. Therefore, it is hard to say that the head having the conventional structure is suitable for a high speed, high image quality, high density ink jet printer.

The piezoelectric element plate is usually made of piezoelectric ceramics, but is very expensive as compared with ordinary ceramics. Therefore, from the viewpoint of utilizing the piezoelectric element plate as effectively as possible, it can hardly contribute to ejection. A head structure that does not have a groove portion and an unground portion is desirable.

Therefore, conventionally, there has been proposed a shear mode ink jet head in which a channel groove is formed straight from the inlet to the outlet, and the entire groove has a straight groove which can contribute to ejection. JP-A-7-132589
No. 9, JP-A-9-20006, JP-A No. 11-11519
5, JP-A-11-115188, JP-A-2000-1
No. 68094, JP-A-2000-141653, JP-A-10-76669 and the like. According to the shear mode inkjet head having such a straight groove, the use amount of the piezoelectric element plate can be minimized.
It has the advantages of small capacitance, excellent high-frequency response, less heat generation, less crosstalk, and less accumulation of bubbles in the channel, making it an excellent head for high image quality, high speed, and high density.

However, since the shear mode ink jet head having the straight channel groove has a structure in which only the portion necessary for ejection is taken out from the head having the conventional structure, the wiring is drawn out from the electrode in the channel groove. However, there is a problem in that it is difficult to secure a space for forming wiring for connecting to the flexible cable. In this case, the lead wires from the electrodes are three-dimensionally formed from the front surface or the rear surface of the head to the bottom surface or the top surface, and the head bottom surface or the top surface is connected to the flexible cable. That is, in such a shear mode ink jet head having such straight channel grooves, it is necessary to form a three-dimensional wiring from the electrodes in the channel grooves to the front surface or the rear surface of the head to the bottom surface or the upper surface. It is very difficult to form such minute three-dimensional wiring with high density.

In recent years, the recording density of ink jet heads has become higher and higher with the aim of achieving high image quality. Corresponding to this, the interval of ink droplets ejected from the head is 90 → 18.
It is as narrow as 0 → 360 dpi. For example, 180 dp
The i-head has to eject ink droplets at 141 μm intervals. In the case of a shear mode inkjet head, this is, for example, a groove width of 71 μm and a wall width of 70 μm. Furthermore, in order to achieve 150 dpi with a head in which ink grooves and air grooves are alternately provided, a groove width and a wall width corresponding to 300 dpi are required, and the width of the groove and the wall is 40 μm.

The number of nozzles is 32 in order to increase the speed.
→ 64 → 128 → 256 → 512 → 1024 Recent heads have a groove width and groove pitch of 40 μm or less,
In some cases, the number of grooves is 1024 or more. As described above, the conventional shallow inlet groove type head is advantageous in forming wiring because the electrode and the lead-out wiring can be formed on substantially the same plane at the same time, but since the response is slow and the heat generation is large, high image quality, Not suitable for high speed heads. On the other hand, a head having a straight groove is advantageous in terms of miniaturization of ejected droplets, high-frequency driving, low heat generation, cost reduction, and crosstalk reduction because it has a structure consisting of only the portion necessary for ejection. The lead wiring from the electrode must be bent three-dimensionally from the front surface or the rear surface of the head to the bottom surface or the top surface to be three-dimensionally formed.

Conventionally, a method of forming a three-dimensional wiring on an electronic component with a plated metal is, for example, after adsorbing a plating catalyst on the surface of a work and irradiating the catalyst with light to deactivate the catalyst in an unnecessary portion for plating. The photo-deposition method is known, but its wiring pitch is on the order of mm, and a method of forming hundreds to thousands of three-dimensional wiring at a pitch of 50 μm or less required for a high image quality inkjet head is known. Absent.

JP-A-7-132589 discloses that a horizontal groove for a straight channel is mechanically ground, a vertical groove is mechanically ground from one end thereof, and after plating, polishing is performed, and a vertical groove is formed in the vertical groove. Form the wiring. In this method, the flutes are mechanically ground so as to overlap with the flutes, and therefore the density cannot be increased so much. Further, since the mechanical grinding is performed twice, when the wall of the groove becomes thin, there is a drawback that the wall easily falls or is easily chipped.

In Japanese Patent Laid-Open No. 9-20006, a straight air groove is formed, and the inlet end of the air groove is closed by a stopper member having a lead wiring, and then a straight ink groove is formed. However, in this method, since the electrode of the air groove and the wiring of the sealing member are in contact with each other at a right angle, highly reliable electrical connection cannot be performed.

JP-A-11-115195 and JP-A-11-115195
No. -115188 is a method in which a member having a conductive contact layer embedded therein is bonded to a piezoelectric element plate, and then an air groove is ground so that the contact layer is exposed. However, with this method, the process becomes complicated, and therefore the fine and precise processing required for manufacturing a high-density head cannot be performed.

In Japanese Patent Laid-Open No. 2000-168094, after plating the entire head, the plating metal deposited between the ink groove and the air groove is linearly removed by laser light to separate the electrodes in each groove. This is a method of forming lead wires at the same time. In this method, the distance between the ink groove and the air groove is 30.
It is as narrow as ~ 70 μm, and as shown in FIG. 16, an adhesive layer 20 that adheres two piezoelectric element plates 201 and 202 together.
Since the laser beam LB is also applied to 3, the adhesive layer 203 is evaporated and destroyed, and the destroyed adhesive layer 2
The ink groove 204 and the air groove 205 are connected by 03, and the ink penetrates into the air groove 205. If the ink enters the air groove 205, the effect of blocking the vibration of the side wall of the groove at the time of ejection is lost, and crosstalk becomes large, which is not preferable. Even if the adhesive layer 203 is less broken, the adhesive layer 2
Laser light L even if ink does not enter from 03
When the metal thin film is evaporated with B, the removed part is dented,
The periphery thereof rises, and further, the metal melt flows out around the periphery and is cooled, solidified and deposited, so that the irregularities become severe and it becomes difficult to completely shield the air groove 205 from the ink in the ink manifold. .

Japanese Unexamined Patent Publication No. 2000-141653 is a method of forming a vertical wiring by masking a rear wall of a head in a pattern with a photosensitive resist, and forming vertical wiring. It is difficult to form a pattern.

Japanese Unexamined Patent Publication No. 10-76669 discloses a technique of providing a via hole at the bottom of a groove, but there is no specific description. Even if a via hole is accurately opened at the stage of a green sheet during the manufacture of a piezoelectric element, if it is sintered at high temperature, expansion and contraction will occur violently.
It is difficult to provide with the positional accuracy of.

[0022]

SUMMARY OF THE INVENTION In summary, as shown in FIG.
In the conventional head as shown in (1), the shallow groove is provided at the end of the channel groove, so when the electrode is formed in the channel groove, the wiring can be automatically drawn out through the shallow groove, but on the other hand, this shallow groove and it The subsequent unground portion hardly contributes to ejection, heat is generated, and crosstalk increases,
It also causes high speed driving.

A head structure suitable for high-quality, high-density, high-speed heads can be obtained by forming straight channel grooves in the piezoelectric element plate, and a portion which does not contribute to ejection is removed from the piezoelectric element plate. Since it has a structure, it has less heat generation, good high frequency response, and has the advantage of saving the use of expensive piezoelectric element plates, but the lead wires connected to the electrodes in the channel groove can be connected to the bottom or front of the head. Or, it must be formed three-dimensionally over the upper surface. It is difficult to draw a three-dimensional wiring bent at 90 ° from the electrode in the channel groove. Such a three-dimensional wiring with a width of several tens of μm bent at a right angle can be
A method for forming a few hundreds to a few thousands and a pitch of several tens of μm has not been known yet.

Further, the piezoelectric element plate is mechanically ground with lateral grooves for channels and vertical grooves for lead-out wiring, and after plating,
In the method of polishing and removing the excess plating metal, the groove with a width of several tens of μm must be ground, so the wall of the groove is easily broken, and the side surface of the head is coated with a photosensitive resist to form a pattern. In the method of forming and plating, the thickness of the head is only 1 to several mm, so apply a resist,
The method of exposing and developing is difficult.

Therefore, an object of the present invention is to form an electrode and a three-dimensional lead wiring by plating, laser light irradiation, and polishing, so that compared with the conventional case, even without performing troublesome image processing and development. A simple and highly reliable method that can form high-density and fine electrodes and high-density and fine three-dimensional wiring, and that does not cause ink leakage or collapse or breakage of partition walls between channel grooves. It is to provide a method for manufacturing an inkjet head.

[0026]

According to a first aspect of the present invention for solving the above problems, in a method for manufacturing a shear mode ink jet head, a plurality of channel grooves are ground in a polarized piezoelectric element plate to form an actuator base. A step of forming, a step of adhering a top plate to the actuator base to form a head base, and irradiating at least one of the front surface and the rear surface of the head base with laser light,
Forming a vertical groove connected to each channel groove of the plurality of channel grooves and an upper surface and / or a bottom surface of the head base; and plating metal on the head base having the vertical groove formed by electroless plating. A step of polishing the front surface and the rear surface of the head substrate to remove the plated metal leaving the plated metal applied to the vertical grooves, and thus the plated metal in each channel groove and the upper surface of the head substrate; And / or a step of forming a vertical wiring connected to the plating metal on the bottom surface and irradiating a laser beam on the upper surface and / or the bottom surface of the head substrate to remove a part of the plating metal, thereby connecting to the vertical wiring. And a step of forming lateral wiring.

According to a second aspect of the present invention for solving the above-mentioned problems, in a method for manufacturing a shear mode ink jet head, a step of grinding a plurality of channel grooves in a polarized piezoelectric element plate to form an actuator base, and the actuator. Forming a head substrate by adhering a top plate to the substrate; and irradiating at least one of the front surface and the rear surface of the actuator substrate with laser light to form each of the channel grooves of the plurality of channel grooves and the head substrate. Forming a vertical groove connected to the bottom surface, applying a plating metal to the head substrate having the vertical groove formed by electroless plating, and polishing the front and rear surfaces of the head substrate to form the vertical groove. By removing the plating metal leaving the plating metal applied to the plate, the plating metal in each channel groove and the head are removed. Forming a vertical wiring connected to the plating metal on the bottom surface of the board, and irradiating the bottom surface of the head substrate with a laser beam to remove a part of the plating metal to form a horizontal wiring connected to the vertical wiring. The method for manufacturing a shear mode inkjet head, comprising:

According to a third aspect of the present invention for solving the above-mentioned problems, in a method for manufacturing a shear mode ink jet head, a step of grinding a plurality of channel grooves in a polarized piezoelectric element plate to form an actuator base, and the actuator. A step of forming a head base by bonding a top plate to the base, and irradiating at least one of the front surface and the rear surface of the top plate with a laser beam to form each channel groove of the plurality of channel grooves and the head substrate. A step of forming a vertical groove connected to the upper surface, a step of applying a plating metal to the head substrate in which the vertical groove is formed by electroless plating,
By polishing the front surface and the rear surface of the head substrate and removing the plated metal leaving the plated metal applied to the vertical grooves, the plated metal in each channel groove and the plated metal on the upper surface of the head substrate are removed. A step of forming vertical wiring connected to the vertical wiring and a step of forming horizontal wiring connected to the vertical wiring by irradiating the upper surface of the head substrate with laser light to remove a part of the plating metal. It is a method of manufacturing a characteristic shear mode inkjet head.

According to a fourth aspect of the present invention for solving the above-mentioned problems, in a method for manufacturing a shear mode ink jet head, a step of grinding a plurality of channel grooves in a polarized piezoelectric element plate to form an actuator base, and the actuator. Forming a head substrate by adhering a top plate to the substrate; and irradiating the front and rear surfaces of the actuator substrate with laser light to connect the channel grooves of the plurality of channel grooves to the bottom surface of the head substrate. Forming grooves every other one of the channel grooves alternately on the front surface and the rear surface of the actuator base, and plating metal by electroless plating on the head base on which the vertical grooves are formed. Process and polishing the front and back surfaces of the head substrate, leaving the plating metal applied to the flutes A step of forming a vertical wiring connecting the plated metal in each of the channel grooves and the plated metal on the bottom surface of the head substrate by removing, and irradiating the bottom surface of the head substrate with a laser beam to remove one of the plated metal. A step of removing a portion to form a horizontal wiring connected to the vertical wiring, and a method for manufacturing a shear mode inkjet head.

According to a fifth aspect of the present invention for solving the above-mentioned problems, in a method for manufacturing a shear mode ink jet head, a step of grinding a plurality of channel grooves in a polarized piezoelectric element plate to form an actuator base, and the actuator. Forming a head substrate by adhering a top plate to the base, and irradiating the front and back surfaces of the top plate with laser light to connect the channel grooves of the plurality of channel grooves to the upper surface of the head base. Forming grooves every other channel groove alternately on the front surface and the rear surface of the top plate; and applying plating metal to the head substrate on which the vertical grooves are formed by electroless plating. Process,
By polishing the front surface and the rear surface of the head substrate and removing the plated metal leaving the plated metal applied to the vertical grooves, the plated metal in each channel groove and the plated metal on the upper surface of the head substrate are removed. A step of forming vertical wiring connected to the vertical wiring and a step of forming horizontal wiring connected to the vertical wiring by irradiating the upper surface of the head substrate with laser light to remove a part of the plating metal. It is a method of manufacturing a characteristic shear mode inkjet head.

The invention according to claim 6 has a step of forming a protective film on the surface of the plated metal of the head substrate on which the plated metal is applied.
The method for manufacturing a shear mode inkjet head according to any one of 1 to 3 above.

The invention according to claim 7 is characterized in that the actuator base is formed by bonding two polarized piezoelectric element plates so that their polarization directions are opposite to each other. It is a method for manufacturing a shear mode inkjet head according to any one of the above.

[0033]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.

First, in this specification, since the direction is important in describing the manufacturing process, the "front surface" and the "rear surface" are
The "top" and "bottom" are clarified respectively. In this specification, the wall surface of the actuator base and the head base that faces the ink ejection side is referred to as a “front surface”, and the wall surface that faces the ink supply side on the opposite side is referred to as a “rear surface”. In all the drawings, the "front surface" is positioned on the back side and the "rear surface" is positioned on the front side. Further, the side to which the top plate is adhered, that is, the upper surface of the top plate is referred to as "upper surface", and the surface opposite to the side to which the top plate is adhered is referred to as "bottom surface". In all the drawings, the “top surface” is located on the upper side and the “bottom surface” is located on the lower side.

As shown in FIG. 1, the first step is to grind the channel groove 2 in the polarized piezoelectric element plate 1 to make the actuator base 3.

There are the following two methods of shearing the side wall of the channel groove 2 formed in the polarized piezoelectric element plate 1.

When the side wall of the channel groove is formed by one polarized piezoelectric element plate, an electrode is formed on the upper half of the side wall and the upper half of the side wall is sheared and deformed. When two polarized piezoelectric element plates are bonded to each other with their polarization directions opposite to each other to form the side wall of the channel groove, an electrode is provided on the side wall, preferably from the viewpoint of improving efficiency, Shear the entire sidewall.

The former method only deforms the upper half of the side wall, while the latter method simultaneously deforms the upper half and lower half of the side wall in opposite directions, so that the amount of deformation is large and the deformation efficiency is high. good. Even if the same voltage is applied, the latter method has a large amount of deformation of the side wall, so that the generated pressure is high, the speed of the ejected ink droplets is high, and therefore the ink landing deviation is small, and the image quality is greatly improved. Also, if the same displacement is given, the latter requires half the voltage, so
The heat generation of the head can be suppressed.

Although any of the above methods can be employed in the present invention, the latter method is preferably used, and as shown in FIG. 1, two polarized plates having different thicknesses (for example, a thickness of 150 μm) are used.
And 900 μm) piezoelectric element plates 1a and 1b are bonded so that the polarization directions thereof are opposite to each other to form a thin plate (piezoelectric element plate 1a).
The channel groove 2 extending from the side to the middle of the thick plate (piezoelectric element plate 1b) is formed, and the channel groove 2 and the partition wall therebetween are provided alternately.

For the piezoelectric element plate 1, a piezoelectric element which is deformed by applying a voltage can be used. A known piezoelectric material can be used for this piezoelectric element. Known piezoelectric materials include piezoelectric materials made of organic materials and non-metallic piezoelectric materials. Particularly, a non-metallic piezoelectric material is preferable, and examples of such a piezoelectric material include piezoelectric ceramics formed through molding and firing steps, piezoelectric materials formed without requiring molding and firing, and the like. Examples of the piezoelectric material made of an organic material include an organic polymer such as polyvinylidene fluoride, a hybrid material of an organic polymer and an inorganic material, and the like.

In the non-metallic piezoelectric material, it is preferable to use lead zirconate titanate (PZT) as the piezoelectric ceramic formed through the steps of molding and firing. Further, BaTiO ₂ , ZnO, LiNbO ₂ , LiTaO ₂
Etc. may be used. As PZT, the true PZT (Pb
ZrO ₂ -PbTiO ₂ ) and modified PZT in which the third component is added to adjust the piezoelectric characteristics. The third component added is Fe, Nb, Ni, Ta, Zn, Mn, Ca,
There are Sb etc.

Further, as the piezoelectric material, piezoelectric powder manufactured by the sol-gel method can also be used. According to the sol-gel method,
The sol is prepared by adding water and an acid or alkali to a homogeneous solution having a predetermined chemical composition and causing a chemical change such as hydrolysis. Further, by subjecting the solvent to a process such as evaporation or cooling, a sol in which fine particles of a target composition or precursors of non-metallic inorganic fine particles are dispersed can be prepared and sintered to obtain a piezoelectric material. It is possible to obtain a compound having a uniform chemical composition, including the addition of a trace amount of a different element. A water-soluble metal salt or metal alkoxide such as sodium silicate is generally used as a starting material, and the metal alkoxide is a compound represented by the general formula M (OR) n, in which the OR group has a strong basicity. Therefore, it is easily hydrolyzed, and changes into a metal oxide or its hydrate through a condensation process like an organic polymer.

Further, as a method of coating a laminated substrate,
There are vapor deposition and sputtering methods that deposit from the vapor phase. There are two methods to create a ceramic substrate from the vapor phase: vapor deposition by physical means and chemical deposition that deposits from the vapor phase on the substrate surface by a chemical reaction. being classified. Further, the physical vapor deposition method (PVD) is subdivided into a vacuum vapor deposition method, a sputtering method, an ion plating method and the like, and the chemical method includes a vapor phase chemical reaction method (CVD), a plasma CVD method and the like.
A vacuum vapor deposition method as a physical vapor deposition method (PVD) is a method of heating a target substance in a vacuum to evaporate it and depositing the vapor on a substrate. The sputtering method is a high energy particle to a target substance (target). Is a method in which atoms and molecules on the target surface exchange momentum with colliding particles to utilize the sputtering phenomenon that is ejected from the surface. The ion plating method is a method of performing vapor deposition in an ionized gas atmosphere. Further, in the CVD method, a compound containing atoms / molecules or ions constituting the film is made into a gas phase state, then introduced into a reaction part with an appropriate carrier gas, and reacted or reacted and deposited on a heated substrate to form the film. Form. In the plasma CVD method, a gas phase state is generated by plasma energy, and 400 ° C. to 500 ° C.
The film is deposited by a gas phase chemical reaction in a relatively low temperature range up to ° C.

As a joining means for joining the two piezoelectric element plates 1a and 1b whose polarization directions are opposite to each other, joining using an adhesive can be adopted, but it is not particularly limited as long as they can be joined. is not. When the adhesive layer is formed using an adhesive, the thickness of the adhesive layer after curing is preferably in the range of 5 to 10 μm.

The means for forming the channel groove 2 is preferably grinding by a known grinding machine. In this embodiment, since the two piezoelectric element plates 1a and 1b are bonded and the channel groove 2 is ground from the piezoelectric element plate 1a side to the middle of the piezoelectric element plate 1b, after the grooves are ground, There is no possibility that the adhesive will overflow into the groove, as compared with the method of Japanese Patent Laid-Open No. 8-174822 in which two piezoelectric element plates are bonded.

As shown in the figure, the channel grooves 2 are ground in the horizontal direction, and both side walls in each channel groove 2 are formed parallel to each other. The shape of the channel groove 2 is such that both side walls of the groove stand upright in the vertical direction and are parallel to each other, so that the inlet (the ink supply side on the rear surface side of the actuator substrate 3) and the outlet (the front surface side of the actuator substrate 3) of the groove are formed. It becomes a straight type with almost the same size and shape on the ink ejection side. The ink groove formed by the straight type channel groove 2 has better bubble removal, higher power efficiency, less heat generation, and better high-speed response than the conventional ink inlet shallow groove type groove. In addition, the amount of expensive piezoelectric element plate used can be greatly saved. The depth of the groove is 150 to 300 μm, the width is 40 to 100 μm,
The length is 1 to 10 mm, and the groove pitch is preferably 80 to 200 μm.

The channel groove 2 thus formed
Can be used as an ink groove that ejects ink and an air groove that does not eject ink, depending on the purpose. In this case, by arranging the ink grooves and the air grooves alternately so that the vibration of ejection does not reach the adjacent ink grooves, it is possible to eject at high speed and simultaneously eject from all ink grooves. Therefore, it is preferable because the printing speed per channel can be greatly improved.

Further, all the formed channel grooves 2 may be used as ink grooves. In this case, in order to prevent crosstalk, the above-mentioned 3-cycle ejection method is preferable. The present invention may be any of them.

When the channel groove 2 is divided into an ink groove and an air groove for use, it is not necessary that all the channel grooves 2 have substantially the same width and the same depth as shown in the drawing. The width and the depth of the air groove may be different.

In the shear mode ink jet head, the period in which ink can be ejected is limited to an integral multiple of the time obtained by dividing the length of the ink groove by the speed of sound in the ink.
In order to eject at high frequency, it is preferable to shorten the length of the ink groove. A straight groove type having a short groove as shown in the drawing is more convenient for high-speed ejection than an inlet shallow groove type having a shallow groove portion.

The next step is to perform the actuator base 3
2 is a step of adhering the top plate 4 to the surface on which the channel groove 2 is formed in to form the head substrate 5 shown in FIG.

As the top plate 4, the actuator base 3 is used.
It is preferable to use a ceramic whose coefficient of thermal expansion is close to that of the piezoelectric element plate 1 used for. For example, it is preferable to use the same piezoelectric element plate (PZT) as the piezoelectric element plate 1 used for the actuator base 3 after depolarizing it.

As a means for joining the actuator base 3 and the top plate 4, an epoxy adhesive is used for bonding, and the weight is 14 to 20 kg.
/ Cm ² pressure and temperature of 90-100 ℃, 3
It is preferable to cure for 0 minutes. Since PZT is expensive, an inexpensive alumina substrate is used as the top plate 4, and this is bonded to the actuator substrate 3 with a room temperature curable adhesive, for example, Able Bond 931-1, 931-1T1N manufactured by Nippon Able Stick Co., Ltd. You may. In this case, since heating is not required at the time of bonding, the difference in thermal expansion coefficient does not matter.

Although not shown in detail, usually, after the actuator base 3 and the top plate 4 are joined, the plurality of heads are cut by cutting the actuator base 3 and the top plate 4 into desired dimensions along a direction orthogonal to the channel grooves 2. The base 5 is formed at the same time.

On the head substrate 5 thus formed, an electrode and a lead wire connected to this electrode are formed in each channel groove 2 by a method described later. When forming the lead-out wiring, first, at least one of the front surface and the rear surface of the head substrate 5 is irradiated with laser light to form each channel groove 2 of the plurality of channel grooves 2 and the upper surface of the head substrate 5 and / or. A vertical groove connecting to the bottom surface is formed.

That is, with respect to the place where the vertical groove is formed, the following modes can be mentioned.

(1) A mode in which it is formed on at least one of the front surface and the rear surface of the actuator base 3. (2) A mode in which it is formed on at least one of the front surface and the rear surface of the top plate 4. (3) A mode in which it is formed on at least one of the front surface and the rear surface of the actuator base 3 and the top plate 4.

Therefore, each of these aspects will be described individually.

(1) Formed on at least one of the front surface and the rear surface of the actuator base 3

When the vertical groove is formed on at least one of the front surface and the rear surface of the actuator base 3, as shown in FIG. 3, at least one of the front surface and the rear surface of the actuator base 3 is irradiated with the laser beam LB, and one end of the channel is formed. A vertical groove 6 which is connected to the groove 2 and whose other end is connected to the bottom surface 5b of the head substrate 5 is formed for each channel 2. In the illustrated example, the vertical groove 6 is formed only on the rear surface of the actuator base 3.

Since the vertical groove 6 is formed not by mechanical grinding but by digging the groove by laser light irradiation, there is no fear of chipping or cracking of the side wall of the groove. Further, it is possible to form a high density of fine grooves that cannot be formed by mechanical grinding. Moreover, since the laser beam is not irradiated between the respective channel grooves 2, even when the two piezoelectric element plates 1a and 1b are used as shown in the present embodiment, the space between the two piezoelectric element plates 1a and 1b is reduced. The adhesive layer is not irradiated with laser light, and the adhesive layer is not destroyed. Therefore, ink leakage due to breakage of the adhesive layer does not occur.

The condition for digging the longitudinal groove 6 with laser light depends on the wavelength and pulse rate of the laser light, but the width is about 30 μm.
m, about 50 J / cm ² to dig a groove with a depth of about 10 μm
The above energy density is required. For example, 4 on the work surface
The second harmonic light of the YAG laser focused at 00 μm ² was emitted with a pulse energy of 0.4 mJ and a pulse rate of 3K.
The vertical groove 6 can be dug by irradiating through the X, Y galvanometer mirror at Hz. The width of this vertical groove 6 is 10
-30 μm is preferable. The depth is 10 to 20μ.
m is preferred.

Next, electroless plating is applied to the entire surface of the head substrate 5 in which the vertical groove 6 is formed in this way to deposit a plating metal.

This electroless plating process is not limited to the pretreatment process.
It consists of a process. As pretreatment, degreasing and etching
And the like. Above
Soaking the substrate 5 in a 0.1% concentration stannous chloride solution
To adsorb stannous chloride, followed by 0.01% salt
Immerse in palladium chloride aqueous solution to adsorb palladium chloride.
The acid between the stannous chloride and palladium chloride adsorbed earlier.
Redox reaction (SnCl ₂+ PdCl₂→ SnCl_Four+ Pd
↓) forms metallic palladium. This metal paradigm
Um serves as a catalyst for electroless plating.

Next, electroless plating is performed on the head substrate 5 on which the catalyst has been adsorbed. The plated metal is deposited on the catalyst adsorption surface of the head substrate 5, and the plated metal forms an electrode.

Ni was used as a metal for forming the electrodes.
(Nickel), Co (cobalt), Cu (copper), Al
(Aluminum), etc., but among these, Ni and C
u is preferable, and Ni is particularly preferable. In electrode formation by electroless plating, Ni-P plating or Ni-B plating may be used alone. Or Ni-P and Ni-
B may be layered. Since the electric resistance of Ni-P plating increases as the P content increases, a P content of about 1 to several% is preferable. Since the B content of Ni-B plating is usually 1% or less, the Ni content is higher than that of Ni-P, the electric resistance is low, and the connectivity with external wiring is good, so that Ni-B is better than Ni-P. Is preferred.

When performing electroless plating, the plating solution is applied not only to the surface of the head substrate 5 but also to the channel grooves 2 and the vertical grooves 6.
It is preferable to vibrate or oscillate the head substrate 5 so that the entire surface is evenly plated and evenly plated.

As described above, the entire surface of the head substrate 5,
That is, electroless plating is also applied to each channel groove 2 and each vertical groove 6.

In the next step, the front and rear surfaces of the head substrate 5 are polished to remove the plated metal deposited on the surface of the head substrate 5, leaving the plated metal in each channel groove 2 and each vertical groove 6. This is the step of forming the electrodes 2a and the vertical wirings 7 as shown in FIG. In the figure, the shaded portion is the portion where the plated metal remains.

In order to remove the plated metal, it may be polished with a usual polishing machine. The polishing by the polishing machine is performed on the head substrate 5
To the front and back of the. Further, the side surface of the head substrate 5 may be polished as necessary, or the non-plated portion may be exposed by cutting the head substrate 5 to a predetermined length after plating.

By polishing as described above, the plating metal on the front and rear surfaces of the head substrate 5 is removed, but the plating metal deposited in the channel grooves 2 and the vertical grooves 6 remains. It is used as the electrode 2a and the vertical wiring 7 connected to the electrode 2a. In addition, since the polishing can smooth the unevenness generated in the laser light irradiation portion, the nozzle plate, the diaphragm plate, and the ink manifold can be reliably bonded in the subsequent process.

Next, as shown in FIG. 5, the bottom surface 5b of the head substrate 5 is irradiated with a laser beam LB to linearly remove a part of the plated metal deposited on the bottom surface 5b substantially parallel to the channel groove 2. By forming the removed portion 9 by means of this, the horizontal wirings 8, 8 ... Connected to the vertical wirings 7 are divided so that each channel groove 2 becomes an independent wiring. The vertical wiring 7 and the horizontal wiring 8 constitute a lead-out wiring led out from the electrode 2a in each channel groove 2.

With this, the lead-out wiring constituted by the vertical wiring 7 and the horizontal wiring 8 can be made independent for each channel groove 2.

When the vertical groove 6 for each channel groove 2 is provided on the front surface of the actuator base 3, the same operation as described above can be performed.

In the mode (1), the vertical groove 6 can be formed on both the front surface and the rear surface of the actuator base 3. In this case, as shown in FIG. 6, the front surface and the rear surface of the actuator base 3 are irradiated with laser light so that each channel groove 2 of the plurality of channel grooves 2 and the head base 5 are exposed.
The vertical groove connected to the bottom surface 5b of the actuator base 3
Formed on both the front and back surfaces of.

In the illustrated example, the actuator base 3
The vertical groove located on the rear surface is designated by reference numeral 6a, and the vertical groove positioned on the front surface is designated by reference numeral 6b, and alternate channel grooves 2 are formed so that the front surface and the rear surface of the actuator base 3 alternate. However, the vertical groove may be formed on both the front surface and the rear surface of the actuator base 3, and is not necessarily limited to the illustrated mode.

After the vertical grooves 6a and 6b are formed, a plating process and a polishing process are performed in the same manner as described above, and then, as shown in FIG.
After forming the electrodes 2a in the respective channel grooves 2 and the vertical wirings 7a and 7b connected to the electrodes 2a by the plated metal remaining in the respective vertical grooves 6a and 6b, as shown in FIG. Irradiate the bottom surface 5b of the with laser light,
By removing a part of the plated metal deposited on the bottom surface 5b in a linear manner, horizontal wirings 8a connected to the vertical wirings 7a and horizontal wirings 8b connected to the vertical wirings 7b are formed. The horizontal wirings 8a and 8b are formed. When forming, the channel groove 2 is divided into an air groove 21 and an ink groove 22 and these are arranged alternately and used, and there is a slight difference in the method when all the channel grooves 2 are used as ink grooves. different.

That is, in the former case, as shown in FIG. 7A, by irradiating the bottom surface 5b of the head substrate 5 with laser light along a direction substantially orthogonal to the channel groove 2, the head substrate 5 is formed. Part of the plating metal is removed linearly so as to separate the front side and the rear side of
One horizontal wiring 8b for the air groove 21 is divided by the plating metal remaining on the front surface side of the head substrate 5, and the plating metal remaining on the rear surface side of the head substrate 5 is divided into
Further, the removal portions 9b, 9b ... Are formed by partially removing linearly in parallel with the channel groove 2 so that each vertical wiring 7a for each ink groove 22 becomes an independent wiring, and the ink groove 2 is formed.
The horizontal wirings 8a for 8 and 8a are divided. In this way, the lead-out wiring constituted by the vertical wiring 7a and the horizontal wiring 8a can be made independent for each ink groove 22.

In the latter case, as shown in FIG. 7 (b), the bottom surface 5b of the head substrate 5 is irradiated with laser light along a direction substantially orthogonal to the channel groove 2 so that the head substrate 5 is exposed. The plating metal is partially removed linearly so as to separate the front surface side and the rear surface side to form a removed portion 9a,
A part of the plated metal remaining on the front surface side of the head substrate 5 is linearly removed in parallel with the channel groove 2 so that each vertical wiring 7b located on the front surface becomes an independent wiring. The removal portions 9b, 9b ... Are formed to form the horizontal wiring 8.
b, 8b ... are classified. Similarly, the plated metal remaining on the rear surface side of the head substrate 5 is partially linearly formed substantially parallel to each channel groove 2 so that each vertical wiring 7a located on the rear surface becomes an independent wiring. Removal and removal unit 9
.. are formed to divide the horizontal wirings 8a, 8a. As a result, the lead-out wiring constituted by the vertical wirings 7a and 7b and the horizontal wirings 8a and 8b can be made independent for each channel groove 2.

According to the former mode shown in FIG. 7 (a), the horizontal wirings 8b connected to all the air grooves 21 may be collectively grounded, so that the wiring formation can be simplified. Moreover, since the density of the lead-out wiring composed of the vertical wiring 7a and the horizontal wiring 8a corresponding to each ink groove 22 can be reduced, the pitch of each lead-out wiring is doubled as compared with the head substrate 5 shown in FIG. It is possible to significantly reduce the risk of causing a defect due to a short circuit by increasing the alignment margin for connecting each lead wire with a flexible cable using an anisotropic conductive film (ACF). You can

In the example shown in FIG. 7A, the removing unit 9
By bending the end portion of a to form the removed portion 9a ′ that is substantially parallel to the channel groove 2, the horizontal wiring 8b is connected to the ink groove 2
It is arranged in parallel with the horizontal wiring 8a constituting the lead wiring for two. In this way, all air grooves 2
There is an advantage that it is possible to collectively arrange the first ground take-out positions on the same side of the bottom surface 5b as the horizontal wiring 8a (here, the rear surface side).

Further, according to the latter mode shown in FIG. 7B, the vertical wirings 7 connected to the respective channel grooves 2 are separately provided on the front surface and the rear surface of the head substrate 5, so that the respective vertical wirings 7 are provided. Since it is possible to reduce the density of the lead wiring formed by the horizontal wirings 8 connected to each other, even though all the channel grooves 2 are used as the ink grooves 22, each lead groove is different from the head substrate 5 shown in FIG. Since the wiring pitch can be doubled, the alignment margin for connecting each lead wiring to the flexible cable by using the anisotropic conductive film (ACF) becomes large, which causes a defect due to a short circuit. The risk can be significantly reduced.

(2) Form on at least one of the front surface and rear surface of the top plate 4

When the vertical groove is formed on at least one of the front surface and the rear surface of the top plate 4, as shown in FIG. 8, at least one of the front surface and the back surface of the top plate 4 is irradiated with laser light,
A vertical groove 6 having one end connected to the channel groove 2 and the other end connected to the upper surface 5a of the head substrate 5 is formed for each channel groove 2. In the illustrated example, the vertical groove 6 is formed only on the rear surface of the top plate 4.

After the vertical groove 6 is formed, the plating step and the polishing step are performed in the same manner as in the above (1), and as shown in FIG.
After forming the electrodes 2a in the respective channel grooves 2 and the vertical wirings 7 connected to the electrodes 2a by the plating metal remaining in the respective vertical grooves 6, the upper surface 5a of the head substrate 5 is irradiated with laser light. , A part of the plated metal deposited on the upper surface 5a is linearly removed in parallel with the channel groove 2 to form a removed portion 9, so that each channel groove 2 becomes an independent wiring. Horizontal wiring 8 connected to wiring 7,
Divide 8 ... By this vertical wiring 7 and horizontal wiring 8,
A lead-out wiring that is led out from the electrode 2a in each channel groove 2 is formed.

With this, the lead-out wiring constituted by the vertical wiring 7 and the horizontal wiring 8 can be made independent for each channel groove 2.

The vertical groove 6 for each channel groove 2 may be provided on the front surface of the top plate 4 in the same manner as described above.

When the vertical grooves 6 are formed on both the front and rear surfaces of the top plate 4, as shown in FIG. 10, the front and rear surfaces of the top plate 4 are irradiated with laser light to form a plurality of channel grooves. Vertical grooves connecting the respective channel grooves 2 of 2 and the upper surface 5a of the head substrate 5 are formed on both the front surface and the rear surface of the top plate 4.

In the illustrated example, the vertical groove located on the rear surface of the top plate 4 is designated by reference numeral 6a, the vertical groove positioned on the front surface is designated by reference numeral 6b, and every other channel groove 2 is connected to the front and rear surfaces of the actuator base 3. However, the vertical groove may be formed on both the front surface and the rear surface of the top plate 4, and is not necessarily limited to the illustrated mode.

After the vertical grooves 6a and 6b are formed, a plating step and a polishing step are performed in the same manner as in the above (1), and as shown in FIGS. 11 (a) and 11 (b), each channel groove is formed. 2 and the vertical wiring 7 connected to the electrode 2a by the plating metal remaining in the vertical grooves 6a and 6b.
After forming a and 7b, the bottom surface 5b of the head substrate 5 is irradiated with laser light to linearly remove a part of the plating metal deposited on the bottom surface 5b, thereby forming a horizontal wiring 8a connected to the vertical wiring 7a. And horizontal wirings 8b connected to the vertical wirings 7b are respectively formed. Here, when forming the horizontal wirings 8a and 8b, each channel groove 2 is formed in the same manner as the embodiment shown in FIGS. 7A and 7B. 21 and the ink groove 22, and when these are alternately arranged and used, each channel groove 2
The method is different from the case where all are used as ink grooves.

That is, in the former case, as shown in FIG. 11A, the upper surface 5a of the head substrate 5 is irradiated with laser light along a direction substantially orthogonal to the channel groove 2 so that the head substrate 5 is exposed. Part of the plated metal is removed linearly so as to separate the front side and the rear side of the head substrate 5 to form the removed portion 9a. The two horizontal wirings 8b are divided, and the plating metal remaining on the rear surface side of the head substrate 5 is lined substantially parallel to the channel groove 2 so that each vertical wiring 7a for each ink groove 22 becomes an independent wiring. Are partially removed to form the removed portions 9b, 9b ... And the lateral wirings 8a, 8a. with this,
The lead-out wiring formed by the vertical wiring 7a and the horizontal wiring 8a can be made independent for each ink groove 22.

In the latter case, as shown in FIG. 11B, the upper surface 5a of the head substrate 5 is irradiated with laser light along a direction substantially orthogonal to the channel groove 2 so that the head substrate 5 is exposed. The plating metal is partially removed linearly so as to separate the front surface side and the rear surface side to form a removed portion 9a,
A part of the plated metal remaining on the front surface side of the head substrate 5 is linearly removed in parallel with the channel groove 2 so that each vertical wiring 7b located on the front surface becomes an independent wiring. The removal portions 9b, 9b ... Are formed to form the horizontal wiring 8.
b, 8b ... are classified. Similarly, the plated metal remaining on the rear surface side of the head substrate 5 is partially linearly formed substantially parallel to each channel groove 2 so that each vertical wiring 7a located on the rear surface becomes an independent wiring. Removal and removal unit 9
.. are formed to divide the horizontal wirings 8a, 8a. As a result, the lead-out wiring constituted by the vertical wirings 7a and 7b and the horizontal wirings 8a and 8b can be made independent for each channel groove 2.

According to the former mode shown in FIG. 11 (a),
7A has the same effect as that of the embodiment shown in FIG.
According to the latter mode shown in FIG. 1 (b), the same effect as the mode shown in FIG. 7 (b) can be obtained.

(3) Actuator base 3 and top plate 4
Of at least one of the front surface and the rear surface of

The vertical groove is used as the actuator base 3 and the top plate 4.
12A and 12B, at least one of the front surface and the rear surface of the head substrate 5 is irradiated with laser light to form a plurality of channel grooves 2. After forming vertical grooves connecting to each channel groove 2 and the upper surface 5a and / or the bottom surface 5b of the head substrate 5 on both the actuator substrate 3 and the top plate 4 constituting the head substrate 5, the plating step, After the polishing process, electrodes 2a are formed in the respective channel grooves 2, and vertical wirings 71 and 72 connected to the electrodes 2a are formed by the plating metal remaining in the respective vertical grooves. Further, the upper surface 5a of the head substrate 5 and The bottom surface 5b is irradiated with laser light, and the top surface 5a
And a part of the plated metal deposited on the bottom surface 5b is linearly removed in parallel with the channel groove 2 to form the removed portions 9, 9 ..., By which an independent wiring is provided for each channel groove 2. , Horizontal wiring 8 connected to the vertical wiring 71, 72
1, 81 ... and 82, 82 ... are classified. With the vertical wiring 71 and the horizontal wiring 81, and the vertical wiring 72 and the horizontal wiring 82,
Lead-out wirings that are led out from the electrodes 2a in the respective channel grooves 2 are formed.

Now, the vertical wirings 71 and 72 and the horizontal wiring 8
The lead-out wiring constituted by 1 and 82 can be made independent for each channel groove 2.

The illustrated example shows an example in which vertical grooves are formed on the rear surface of the head substrate 5, and FIG. 12A shows a state in which the head substrate 5 is viewed from the upper surface 5a side. )
Shows the same head substrate 5 viewed from the bottom surface 5b side.

In the illustrated example, the vertical wiring formed by the vertical groove on the actuator base 3 side is designated by reference numeral 71, and the vertical wiring formed by the vertical groove on the top plate 4 side is designated by reference numeral 72.
It is shown that every other channel groove 2 is alternately formed on the actuator base 3 side and the top plate 4 side, but in this mode, the vertical grooves form the front faces of the actuator base 3 and the top plate 4, and It need only be formed on at least one of the rear surfaces, and is not necessarily limited to the illustrated embodiment.

According to this aspect, the lead wiring connected to the electrode 2a of each channel groove 2 is connected to the upper surface 5 of the head substrate 5.
Since it can be divided into a and a bottom surface 5b, it is necessary to connect to the flexible cable at the top surface 5a and the bottom surface 5b of the head substrate 5, but when all the channel grooves 2 are used as ink grooves, they are pulled out. Both the wiring pitch and the area of each lead-out wiring can be made large, and the margin at the time of alignment for connecting each lead-out wiring with the flexible cable using the ACF becomes larger, causing a defect due to a short circuit. The risk can be further reduced.

When each channel groove 2 is used as an ink groove and an air groove and these are alternately arranged, as shown in the figure, every other channel groove 2 is connected to the actuator base 3 side and the ceiling. If vertical grooves are alternately formed on the plate 4 side, although not shown in detail, either the upper surface 5a or the bottom surface 5b of the head substrate 5 can be used as the lead wiring for the air groove as it is. Therefore, in the process of forming the lead wiring after the plating process and the polishing process, it is not necessary to irradiate the surface of the lead wiring for the air groove with a laser beam to divide the lead wiring. You can

Incidentally, in the mode in which the vertical groove is formed on at least one of the front surface and the rear surface of the actuator base 3 and the top plate 4 by the irradiation of the laser light, it is not limited to the case where one vertical groove is formed in each channel groove 2. As shown in FIG.
In each of the channel grooves 2, vertical grooves are formed on both the actuator base 3 and the top plate 4, and after the plating process and the polishing process, the plating metal remaining in the vertical grooves causes the inside of each channel groove 2 to grow. Vertical wirings 71 and 72 connected to the electrode 2a may be formed respectively.
All the vertical grooves may be provided on either the front surface or the rear surface of the head substrate 5, for example, the vertical wiring 71 is provided on the front surface of the actuator substrate 3 and the vertical wiring 72 is provided on the rear surface of the top plate 4. Of course, the head base 5 may be separately provided on the front surface and the rear surface.

The illustrated example shows an example in which all the vertical wirings 71 and 72 are formed on the rear surface of the head substrate 5, as shown in FIG.
3 (a) shows a state where the head substrate 5 is viewed from the upper surface 5a side,
FIG. 13B shows the same head substrate 5 as viewed from the bottom surface 5b side.

In this case, the upper surface 5a and the bottom surface 5b of the head base 5 are irradiated with laser light, respectively, in the same manner as in FIG. 5 or FIG. Each of the channel grooves 2 is formed by linearly removing a part of the plated metal deposited on 5b in parallel with the channel grooves 2 to form the removed portions 9, 9.
The vertical wirings 71 and 72 are arranged so that the wirings are independent of each other.
The horizontal wirings 81, 81 ... And 82, 82.

According to this aspect, the upper surface 5 of the head substrate 5 is
Since the lead wiring of the same pattern is formed on the a and the bottom surface 5b, when all the channel grooves 2 are used as ink grooves, the connection surface with the flexible cable may be either the top surface 5a or the bottom surface 5b. it can.

As described above, after the electrodes 2a and the lead wires connected to the electrodes 2a are formed on the head substrate 5 as shown in each of the modes (1) to (3), as shown in FIG. The nozzle plate 10 is bonded to the front surface, and the diaphragm plate 11 and the ink manifold 12 are bonded to the rear surface of the head substrate 5. Here, an example using the head substrate 5 shown in FIG. 5 is shown.

The nozzle plate 10 is generally a sheet-like thin plate made of stainless steel or polyimide, and nozzle holes 10a for ejecting ink are provided corresponding to each channel groove 2. For example, a polyimide sheet of 125 μm is formed with 18 μm diameter nozzle holes 10 a in accordance with the number of channel grooves 2 and perforated by excimer laser light.
This is bonded to the front surface of the head substrate 5 with an epoxy adhesive.

The diaphragm plate 11 is provided in order to restrict the ink inlet flow path and prevent the pressure applied to the ink during ejection from leaking to the manifold side. In this diaphragm plate 11, for example, a 125 μm polyimide sheet is provided with ink supply holes 11 a having a diameter of 20 to 30 μm in accordance with the number of channel grooves 2 by excimer laser light, and is bonded to the rear surface of the head substrate 5 with an epoxy adhesive. And subsequently cured at 80 ° C. for 40 minutes.

The ink manifold 12 is obtained by adhering a molded product obtained by injection molding an engineering plastic, for example, a polyetherimide resin, to the rear surface of the head substrate 5 with an epoxy adhesive.

Although not shown, each horizontal wiring 8 formed on the bottom surface 5b or the top surface 5a of the head substrate 5 is formed by using an anisotropic conductive film (ACF) at about 170 ° C. for about 20 seconds.
By uniformly applying a load of about 4 kg and heating and pressing, a flexible cable connected to a drive control board (not shown) is electrically connected.

In the manufacturing method described above, after the head substrate 5 is electroless plated, a protective film is formed on the plated metal in order to prevent corrosion due to contact of the deposited plated metal surface with the ink. It is preferably formed. The protective film forming step may be performed after the electroless plating is applied to the head substrate 5, and may be performed before or after the formation of the lead wiring by the irradiation of the laser light.

As the protective film, it is preferable to use an organic insulating film. The method of forming the organic insulating film includes a coating method and an electrodeposition method. Examples of the coating method include a method of spin coating a polymer film on the electrode and a method of conformal coating, and an organic film formation by a dry method, for example, parylene conformal coating may be used.

As a method of forming the organic insulating film by the electrodeposition method, for example, the head substrate 5 having the electrodes formed thereon is immersed in an electrodeposition liquid containing a 15% aminoacryl resin at room temperature, and a direct current of 50 V is applied. When applied for 2 minutes, a pinhole-free insulating film having a thickness of about 2 μm is formed. In the electrodeposition method, a film is formed only in a conductive place, and once a thin film is formed, that part is insulated and loses conductivity, so it is not deposited in that place. Instead, since another conductive place is searched for and deposited, a uniform thin film can be coated even on a complicated shape. As described above, the electrodeposition method is preferable because a thin organic insulating film can be easily formed uniformly up to the bottom of the fine groove.

[0113]

According to the present invention, a piezoelectric element plate is mechanically ground to form a channel groove, and a vertical groove connected to the channel groove is formed by irradiating laser light, and then electroless plating is performed to form a head substrate. To form vertical wiring by irradiating the head substrate with laser light and to form horizontal wiring connected to this vertical wiring. The method is simpler than the image processing method using, and the electrodes and the lead wirings connected to the electrodes can be easily formed without chipping or falling of the sidewall of the groove.

Even when the two piezoelectric element plates are adhered together to form the actuator substrate, the adhesive layer is not irradiated with laser light, so that ink leakage due to destruction of the adhesive layer does not occur. Absent.

[Brief description of drawings]

FIG. 1 is a perspective view of an actuator base and a top plate showing a process of a manufacturing method of the present invention.

FIG. 2 is a perspective view of a head substrate showing a process of the manufacturing method of the present invention.

FIG. 3 is a perspective view of a head substrate showing a process of the manufacturing method of the present invention.

FIG. 4 is a perspective view of a head substrate showing a process of the manufacturing method of the present invention.

FIG. 5 is a perspective view of a head substrate showing a process of the manufacturing method of the present invention.

FIG. 6 is a perspective view of a head substrate showing the process of the manufacturing method of the present invention.

7 (a) and 7 (b) are perspective views of the head substrate showing the steps of the manufacturing method of the present invention.

FIG. 8 is a perspective view of a head substrate showing a process of the manufacturing method of the present invention.

FIG. 9 is a perspective view of a head substrate showing a process of the manufacturing method of the present invention.

FIG. 10 is a perspective view of a head substrate showing a process of the manufacturing method of the present invention.

11 (a) and 11 (b) are perspective views of the head substrate showing the steps of the manufacturing method of the present invention.

12 (a) and 12 (b) are perspective views of the head substrate showing the steps of the manufacturing method of the present invention.

13 (a) and 13 (b) are perspective views of a head substrate showing the steps of the manufacturing method of the present invention.

FIG. 14 is a perspective view of the head substrate showing the process of the manufacturing method of the present invention.

FIG. 15 is an explanatory diagram of a conventional inlet shallow groove structure.

FIG. 16 is an explanatory view of a conventional laser light irradiation method.

[Explanation of symbols]

1: Piezoelectric element plate 2: Channel groove 2a: electrode 3: Actuator base 4: Top plate 5: Head substrate 6, 6a, 6b: vertical groove 7, 7a, 7b: Vertical wiring 8, 8a: Horizontal wiring 9, 9a, 9b, 9c: Removal unit 10: Nozzle plate 10a: nozzle hole 11: diaphragm plate 11a: ink supply port 12: Ink manifold

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 2C057 AF35 AG12 AG44 AG45 AG93                       AP03 AP14 AP22 AP23 AP25                       AP55

Claims (7)

[Claims] 1. A method for manufacturing a shear mode ink jet head, comprising the steps of grinding a plurality of channel grooves in a polarized piezoelectric element plate to form an actuator base, and bonding a top plate to the actuator base to form a head base. A step of forming, and irradiating at least one surface of the front surface and the rear surface of the head substrate with a laser beam to form a vertical groove connected to each channel groove of the plurality of channel grooves and an upper surface and / or a bottom surface of the head substrate. A step of forming, the step of applying a plating metal to the head substrate in which the vertical groove is formed by electroless plating, a front surface and a rear surface of the head substrate are polished, and the plating metal applied to the vertical groove is formed. By removing the plating metal remaining, the plating metal in each channel groove and the top and / or bottom surface of the head substrate are plated. A step of forming a vertical wiring connected to the metal, and a laser beam is applied to the upper surface and / or the bottom surface of the head substrate to remove a part of the plating metal, thereby forming a horizontal wiring connected to the vertical wiring. A method for manufacturing a shear mode inkjet head, comprising: 2. A method of manufacturing a shear mode ink jet head, comprising the steps of forming a plurality of channel grooves on a polarized piezoelectric element plate to form an actuator base, and bonding a top plate to the actuator base to form a head base. A step of forming, and a step of irradiating at least one surface of the front surface and the rear surface of the actuator substrate with a laser beam to form a vertical groove connected to each channel groove of the plurality of channel grooves and the bottom surface of the head base; A step of applying plating metal to the head base having the vertical grooves formed thereon by electroless plating, and polishing the front and rear surfaces of the head base to leave the plating metal applied to the vertical grooves. By removing the vertical distribution that connects the plated metal in each channel groove and the plated metal on the bottom surface of the head substrate. And a step of forming horizontal wirings connected to the vertical wirings by irradiating the bottom surface of the head substrate with laser light to remove a part of the plating metal. Yermode inkjet head manufacturing method. 3. A method for manufacturing a shear mode ink jet head, comprising the steps of forming a plurality of channel grooves in a polarized piezoelectric element plate to form an actuator base, and bonding a top plate to the actuator base to form a head base. A step of forming, and a step of irradiating at least one of the front surface and the rear surface of the top plate with a laser beam to form a vertical groove connected to each channel groove of the plurality of channel grooves and the upper surface of the head substrate, A step of applying plating metal to the head base having the vertical grooves formed thereon by electroless plating, and polishing the front and rear surfaces of the head base to leave the plating metal applied to the vertical grooves. To form a vertical wiring connecting the plated metal in each channel groove and the plated metal on the upper surface of the head substrate. Irradiating a laser beam on the upper surface of the head substrate to remove a part of the plating metal to form a horizontal wiring connected to the vertical wiring. Production method. 4. A method for manufacturing a shear mode ink jet head, comprising the steps of forming a plurality of channel grooves in a polarized piezoelectric element plate to form an actuator base, and bonding a top plate to the actuator base to form a head base. Forming step, and irradiating the front and back surfaces of the actuator substrate with laser light to form vertical grooves connecting to each channel groove of the plurality of channel grooves and the bottom surface of the head substrate, every other one of the channel grooves. A step of alternately forming a front surface and a rear surface of the actuator base; a step of applying plating metal to the head base having the vertical grooves formed thereon by electroless plating; and a front surface and a rear surface of the head base. By polishing and removing the plating metal leaving the plating metal applied to the flutes, A step of forming a vertical wiring connected to the plated metal in the groove and the plated metal on the bottom surface of the head base, and by irradiating the bottom surface of the head base with a laser beam to remove a part of the plated metal, And a step of forming horizontal wirings connected to the vertical wirings. 5. A method for manufacturing a shear mode ink jet head, comprising the steps of forming a plurality of channel grooves on a polarized piezoelectric element plate to form an actuator base, and bonding a top plate to the actuator base to form a head base. Forming step, and irradiating the front and rear surfaces of the top plate with a laser beam to form vertical grooves connecting to each channel groove of the plurality of channel grooves and the upper surface of the head substrate, every other channel groove. A step of alternately forming the front and rear surfaces of the top plate; a step of applying a plating metal to the head base on which the vertical grooves are formed by electroless plating; and a front and rear surface of the head base. By polishing and removing the plating metal leaving the plating metal applied to the vertical grooves, the plating metal in each of the channel grooves and the head substrate are removed. A step of forming a vertical wiring connected to the plating metal on the upper surface of the head substrate, and irradiating the upper surface of the head substrate with a laser beam to remove a part of the plating metal to form a horizontal wiring connected to the vertical wiring. A method for manufacturing a shear mode inkjet head, comprising: 6. The shear mode inkjet according to claim 1, further comprising a step of forming a protective film on the plated metal surface of the head substrate on which the plated metal is applied. Head manufacturing method. 7. The actuator substrate is polarized 2
7. The method for manufacturing a shear mode inkjet head according to claim 1, wherein the piezoelectric element plates are adhered so that the polarization directions thereof are opposite to each other.